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This paper describes the theory, design, implementation, simulation, and testing of an ASIC capable of generating false target radar images for countering wideband synthetic aperture and inverse synthetic aperture imaging radars. The 5.5 x 6.1 mm IC has 81632 transistors, 132 I/O pins, and consumes 0.132 W at 70 MHz from a 3.3-V supply. An introduction to the application and operation of the ASIC in an electronic attack system is also presented. The false target image is fully programmable and the chip is capable of generating images of both small and large targets, even up to the size of an aircraft carrier. This is the first reported use of all-digital technology to generate false target radar images of large targets.

Early experiences may alter later behavioural expressions in animals and these differences can be consistent through adulthood. In dogs, this may have a profound impact on welfare and working ability and, it is therefore interesting to evaluate how experiences during the first weeks of life contribute to shaping the long-term behaviour. We analysed data from 503 dogs from 105 litters, bred at the Swedish Armed Forces Dog Kennel. For each dog, the data comprised information on dam and sire, sex, litter size, sex ratio of litter, date of birth, and weight at birth, and at 10 days of age. Between the ages of 377 and 593 days, the dogs were tested in a temperament test, assessing their suitability as working dogs. The behaviour test comprised 12 different sub-tests, and was scored on a behavioural rating scale. A principal component analysis showed that the test performance could largely be attributed to four principal components (explaining 55.7% of variation), labelled Confidence, Physical Engagement, Social Engagement and Aggression. We analysed the effects of the different early life variables and sex on the principal component scores (PC scores) using linear modelling. PC scores on Confidence were affected by parity, sex and litter size, and Physical Engagement was affected by parity, growth rate, litter size and season of birth. Social Engagement was affected by growth rate and sex, and Aggression was affected by sex. Some of these effects disappeared when they were combined into a single linear model, but most of them remained significant also when controlling for collinearity. The results suggest that the early environment of dogs have long-lasting effects on their behaviour and coping styles in a stressful test situation and this knowledge can be used in the work with breeding of future military or police working dogs.

Domestication has resulted in animals with broad variations between as well as within breeds, which allows for the selection and breeding of animals for preferred traits. This selection has affected both the genotypes and phenotypes of animals. In dogs, it has allowed for breeding for different purposes, such as companionship or the performance of specific tasks, e.g., herding, hunting, searching and protecting. Each of these types of working dogs has specific traits that are, in part, controlled by genes; however, genes are not solely responsible for the variations in the traits of an individual. The environment also plays a role, which has been studied in rodents and primates in recent decades. For instance, it has been shown that the amount of maternal care that a rat receives as a pup affects its temperament later in life; the more maternal care, i.e., licking, grooming and arched-back nursing (LG-ABN), that a rat receives, the more stress resistant, less reactive and more explorative it will be as an adult. However, the question is whether this is also true for dogs, and the investigation of how temperament in dogs is affected by environmental factors early in life is the main objective of this thesis. Three of the studies presented in this thesis focused on investigating the general parameters, particularly maternal care, that influences offspring behaviour to contribute to the understanding of temperament development in military working dogs. One of these studies concentrated on the environmental factors that influence dogs early in life, and the results indicated that some factors, such as parity, litter size and birth season, affect temperament later in life. Another study investigated how females take care of their young, and the results demonstrated that females consistently vary in their maternal style during the first three weeks postpartum and that this variation affects the temperament of the offspring. The third study focused on factors in the home environment, and the results showed that dogs approved through the evaluative temperament test were significantly associated with being hyperactive or restless and having difficulty settling down in the home environment. However, those dogs were also left home alone for more hours in a day than non-approved dogs. To be able to operate functionally, a military working dog needs to possess certain traits, or a certain temperament, and a vital characteristic is the way it responds to and copes with stress. This was investigated during an evaluative temperament test used to select dogs suitable for further training. Surprisingly, the results showed that the dogs approved for further training had significantly higher levels of salivary cortisol both before and after the test compared with the non-approved dogs. These findings may be of profound importance for understanding individual variations in behaviour and improving breeding schemes for working dogs.

Early life experiences are known to shape the behavioural development of animals, and therefore events occurring during preadolescence and adolescence may have long-term effects. In dogs, this period of time may be important for later behaviour and thereby also the suitability of dogs for different working tasks. We used the breeding practice for Swedish military working dogs to investigate this possibility. German Shepherds were bred at a central facility and then kept in host families for about a year, before participating in a standardised test determining their temperament, behaviour, and suitability for further training. We surveyed the link between the behaviour of 71 prospective military working dogs in their home situations during the first year of life as assessed by an amended C-BARQ survey, and their performance in a temperament test (T-test) applied at about 17 months of age. Dogs which scored high for C-BARQ category "Trainability" showed a significantly higher success rate in the T-test (P < 0.001), while dogs that scored high for "Stranger-directed fear", "Non-social fear" and "Dog-directed fear" showed a significantly lower success rate (all P < 0.05). Also dogs with higher C-BARQ scores on "Hyperactivity/restlessness, difficulties in settling down" (P=0.028), and "Chasing/following shadows or light spots" (P=0.035) were more successful, as were dogs left longer times at home (2.97 +/- 0.32 vs. 2.04 +/- 0.33 h/day; P=0.050). Index value, describing the expected success rate in the T-test, was negatively correlated with "Non-social fear" (r = -0.35) and "Stranger directed fear" (r = -0.35). The combined effect of the significant C-BARQ categories explained 29.5% of the variance in the later T-test results (P=0.006). The results indicate that the experiences and behaviour of the dogs during their first year of life is crucial in determining their later behaviour and temperament, something that could potentially be used to improve selection procedures for working dogs. Furthermore, an unsuspected result was that success in the T-test was correlated with behaviours usually associated with problem behaviour, which calls for a deeper analysis of the selection criteria used for working dogs. (C) 2014 Elsevier B.V. All rights reserved.

Military and police working dogs are often exposed to stressful or threatening events, and an improper response, e.g., fear, may implicate both reduced working efficiency and welfare. Therefore, identifying individuals that display a favorable response to potentially threatening situations is of great interest. InÂ the present study, we investigated behavior responses of 85 prospective military working dogs in 4 subtests in a standardized temperament test used to select working dogs for the Swedish Armed Forces. Our goal was to evaluate behavioral responses in specific subtests and cortisol responses of candidate dogs. After dogs were rated as approved or nonapproved based on the test leader’s assessment of the full test result, we independently analyzed video recordings of 4 subtests. In addition, for 37 dogs, we analyzed pretest and posttest salivary cortisol levels. Dogs which were approved by the test leader for further training scored higher in the video recordings on emotionality and, in particular, fear-related behavior during a subset of the test and had higher levels of cortisol both before and after the test, than nonapproved dogs. Although this may actually reflect the desired traits, it could also indicate a bias in the selection procedure, which may pose limitations on the attempts to recruit the most suitable working dogs.

Dog puppies are born in a state of large neural immaturity; therefore, the nervous system is sensitive to environmental influences early in life. In primates and rodents, early experiences, such as maternal care, have been shown to have profound and lasting effects on the later behaviour and physiology of offspring. We hypothesised that this would also be the case for dogs with important implications for the breeding of working dogs. In the present study, variation in the mother-offspring interactions of German Shepherd dogs within the Swedish breeding program for military working dogs was studied by video recording 22 mothers with their litters during the first three weeks postpartum. The aim was to classify mothers with respect to their level of maternal care and to investigate the effect of this care on pup behaviour in a standardised temperament test carried out at approximately 18 months of age. The results show that females differed consistently in their level of maternal care, which significantly affected the adult behaviour of the offspring, mainly with respect to behaviours classified as Physical and Social Engagement, as well as Aggression. Taking maternal quality into account in breeding programs may therefore improve the process of selecting working dogs.

There are several examples of failed arms acquisition programs, where costs have been underestimated, and unproven technology misunderstood.

Arms acquisition programs seem to suffer from particular difficulties, judging from the results obtained. This is not only a U.S., and to some extent U.K., phenomenon, although the debate is by far most active in those two nations. The problems express themselves as cost overruns, delayed deliveries, and fundamental, sometimes insoluble, technical challenges. The term “acquisition” is here used for the complete life cycle process of a system, covering concept generation, design phase, prototypes, volume production, operational use, various upgrades, and disposal. The problems are typically, but not always, encountered in the design phase.

Is military acquisition inherently more difficult than similar programs in non-military business areas? The fact that these programs are usually paid for by public money, that large sums of money are involved, and that programs often are not competed, all contribute to making these programs much more prone to extensive media coverage, in particular concerning any failures, compared to similar big-money, high-tech programs in the private sector.

In this paper we will examine the technologies involved and their sometimes extraordinary pace of development, some inherent difficulties with big military programs, the fundamental difficulties with cross-border collaboration and the funding challenges in times of austerity, and we will propose some remedies.2We believe that the conclusions of this paper are relevant e.g. for the ongoing negotiations for Sweden-Brazil military cooperation and arms acquisition.

The Aeronautics RTD programme in Sweden was in the past dominated by the needs for the development of military aircraft and this programme is still continued to support the Gripen but with a lower level of effort. The national Aeronautical Programme (NFFP) started in 1994 and is now in its fifth phase (2009-2012). Its objectives are to: (i) strengthen Swedish competitiveness; (ii) strengthen the capability to participate in international research cooperation; (iii) support Swedish Armed Forces.

GARTEUR (Group of Aeronautical Research and Technology in EU-Rope) is a multinational organisation that performs high quality, collaborative, pre-competitive aeronautical research. It is based on a government-to-government agreement (MoU) between seven European nations with major research and test capabilities in aeronautics. GARTEUR was formed in 1973 by the governments of France, Germany and the United Kingdom in the wake of the formation of Airbus. The Netherlands joined the group in 1977. Sweden joined GARTEUR in 1991, followed by Spain in 1996 and Italy in the year 2000. The GARTEUR focus is on research topics aimed at long term R&T because this is considered essential to assure sustained competitiveness of the European aerospace industries. A key asset of GARTEUR is its unique mechanism for cooperation, which has been used successfully for numerous collaboration projects over the past decades. It is the only framework in Europe for both civil and military aeronautics R&T.

If students really understand the systems they study, they would be able to tell how changes in the system would affect a result. This demands that the students understand the mechanisms that drive its behaviour. The study investigates potential merits of learning how to explicitly model the causal structure of systems. The approach and performance of 15 system dynamics students who are taught to explicitly model the causal structure of the systems they study were compared with the approach and performance of 22 engineering students, who generally did not receive such training. The task was to bring a computer-simulated predator-and-prey ecology to equilibrium. The system dynamics students were significantly more likely than the engineering students to correctly frame the problem. They were not much better at solving the task, however. It seemed that they had only learnt how to make models and not how to use them for reasoning.

This chapter proposes an approach to modelling the functions of C2 performed over a network of geographically distributed entities. Any kind of command and control (C2) organisation, hierarchical, networked, or combinations thereof, can be represented with this approach. The chapter also discusses why a theory of C2 needs to be expressed in functions in order to support design and evaluation of C2 systems. The basic principle of how to model functions performed by network is borrowed from Cares’ network model of warfare, which is also used to model the context in which C2 is performed. The approach requires that C2 is conceived of as fulfilling a set of necessary and sufficient functions. Brehmer proposes such a theoretical model that is at a sufficiently high level of abstraction to illustrate the suggested approach. More detailed models will be required, however, for the approach to be of practical use.

The wide use of light anti-tank weapons, such as rocket propelled grenades and the scattering of sub-munitions lead toa greatnumber of explosive remnants of war (ERW) containing shaped charge warheadsin different conflict areas. A serious problem is that, the explosive ordnance disposal (EOD) personnel lack adequate means for the design of protective measures against the jetfrom clearance of shaped charge ammunition. In this paper, based on a master thesis in military technology,a previously suggested calculation model1, is developed further. The objectiveis to create a tool that can be applied to EOD operationsand meet military requirements by consideration of the limited information availability, the short time frames, the working methods and the technology level that are characteristic for such operations.

Full-scale experiments have been conducted to clarify the effects of conditions that are typical for EOD operations: protective measures built from sandbags with a long standoff distance to the ordnance. The results indicate that the hydrodynamic penetration theory is not suitable for these conditions,and,furthermore, thata sandbag construction provides significantly better protection against the jet than a homogeneous gravel construction.

By disturbance analysis, the sensitivity of the individual parameters in the model is studied for typical errors. Subsequently, Monte Carlo simulation has been used to analyse the cumulative effect these errors can cause. The simulation results have then been the used to determine the model ́s margin of safety.

To achieve the desired military utility it should be possible to use the model under field conditions, with limited time frames and without access to advanced calculating means. This has resulted in a simple diagram included in a completedesign tool.It is proposed to implement the toolin regulations and curricula for EOD operations in order to remedy today’s lack of decision support

Protective measures must often be established during explosive ordnance disposal (EOD) operations to reduce the effects of unexploded ordnance (UXO). Adequate models for the design of protective constructions against the jet from shaped charge ammunition are lacking. Two conditions are unique for EOD operations on shaped charges: constructions built from sandbags and long standoff distances. For these conditions, verified test data are very limited.

To study these conditions, full-scale experiments have been conducted at the Swedish EOD and Demining Centre (SWEDEC) with the objective to generate data for the development of a useful tool for EOD operations. Three series of five shots using a 107 mm warhead have been fired against both sandbag and homogenous sand/gravel targets, at standoff distances from 10 to 100 calibers.

The result indicates that the hydrodynamic penetration theory, based on the Bernoulli equation, is not suitable for these target materials and these standoff distances. The actual penetration was more than twice what was expected from calculations based on this theory. Furthermore, the penetration was found to be significantly smaller when the sand/gravel was packed in sandbags – a result in contradiction to the same theory.

Standoff curves which also take into account if the target material is packed in sandbags or not have been developed. The general shape of these curves is different from what is characteristic for materials such as metals and concrete. Increasing standoff decreases penetration only marginally.

The jet is fully fragmented into smaller segments when it hits the target, but still has good penetration capability in these target materials. This phenomenon is related to the cut-off velocity, the lowest jet velocity that gives a contribution to the penetration, which is considerably lower than for more resistant target materials. Combining the influence of the cut-off velocity with the hydrodynamic penetration theory is used in the explanatory model in the paper.

The experiments also demonstrated that the target material surrounding the jet moved forward, resulting in a growing penetration channel after the jet was fully consumed. This is related to phase three penetration. The contribution to the total penetration is considerable and gives a plausible explanation as to why sandbags give better protection.

The results have been used to develop a new model for the design of protective measures against jet penetration. The military utility for EOD operations has been the main criteria during all development phases. The final result is a simple tool that can be used under field conditions. Approximately one year after the first experiments, the result has been implemented in regulations and training for EOD personnel in the Swedish Armed Forces.

Life is full of risks – in war and peace. Risks that we often try to avoid, eliminate or - at least - reduce. Military activities often include risks – in war requiring excessive countermeasures but also in peacetime situations and during international military missions where competent risk reducing actions must be searched for.

Military Technology within SNDU focuses research on military utility as a measure when evaluating technical systems for military purposes. The definition of military utility often must be different for different applications and measured in different units, e.g. economic costs, cost in time to complete a task or costs in human lives - or even combinations of units for different systems.

A recent research program at SNDU handles risks in explosive ordnance disposal (EOD) operations based upon the military utility.

The wide use of light anti-tank weapons and the scattering of sub-munitions have made clearance of unexploded ordnance containing shaped charge warheads - a frequent task for EOD personnel.

Several circumstances are characteristic for EOD operations and have to be taken into consideration when evaluating the military utility: the limited information availability, the short time frames, the working methods and the technology level.

Protective measures such as evacuation of a hazardous area or building of a protective construction often have to be executed to reduce risks. Two conditions are unique for protective constructions in EOD operations on shaped charge ammunition: constructions built from sandbags and long standoff distances.

As has been shown in earlier ISMS annual conferences measures to handle risks were identified and acted upon in the SNDU program[i],[ii].

The result up until now is a tool meeting the military requirements - e.g. which can be used under field conditions, within a limited time frame and without access to advanced calculating equipment. The format is a simple diagram included in a complete design tool.

This tool is now being implemented in regulations and training for EOD personnel in the Swedish Armed Forces.

The result reached so far fill a gap, but it does not represent the ultimate solution for risk handling –it rather form a step forward within EOD operations. The tool, however transparent and based upon verified tests, only handles the two cases: either full countermeasures or no countermeasures. This binary approach to risk factors is not unique for this situation, many methods and tools are designed for extrema, nothing in between.

To establish a protective construction that completely eliminates the risk is often not possible, simply because the large dimensions require resources or time to complete the construction that are not available.

What if only partial protection is possible– what risk does that leave us with?

The surroundings also affect the actual risk. Infrastructure, terrain formations and vegetation can both decrease and increase the effects from the ammunition. Furthermore, what influence do different render safe procedures and applied clearance charges have on the risk? Only suitable tools that consider the actual influence of these aspects will provide the necessary foundation for estimation of a more correct risk. Here we are still without rules to apply.

Basic questions like “What risk is acceptable?”, “During what conditions?” and “How do we reach acceptable risk levels?” remain to be answered. Furthermore, we have to develop how we communicate the risk to decision makers, particularly in extreme situations. If a risk described in mathematical format is not rightly understood by everyone other formulations that are perfectly clear must be used.

We know that the attitude towards risks varies with individuals, with the situation and over time but we do not have vehicles to give us adequate quantitative measures. The answers to questions on acceptable risk not only relate to technical issues but also comprise military judgement, leadership and communications as well as they have judicial and ethical dimensions.

The objective for future research in the field is a dynamic risk management model comprising also other situations than those studied up until now and to evaluate and appreciate alternative mitigation measures along the chain of clearance activities.

A dynamic risk management concept developed for EOD operations should be a step in the handling of the general threat from explosive remnants of war, i.e. land mines, UXO:s and IED:s, which often have significant impact on a military operation as a whole. These threats exist on all levels of conflict and their constantly changing character requires a dynamic approach when it comes to risk handling.

War fighting is evolving, with a continuous struggle between our measures and the opponents countermeasures. There is no clear distinction between friend and foe, peace and war or danger and safety - military activities take place in a grey-zone. Supportive programs have to be adapted to this reality and methods for dynamic risk management tailored for military operations. The military utility of such a concept is obvious with good possibilities to generalisation, a worthwhile starting point for dynamic risk handling methods for other military activities.

The paper is focused on a dynamic risk management concept where not only technical issues are dealt with, but also other military concerns are addressed with the military utility as a basic measure.

The clearance of unexploded ordnance (UXO) and other explosive remnants of war (ERW) containing shaped charge warheads poses a particular technical hazard to consider for explosive ordnance disposal (EOD) personnel. The wide use of light anti-tank weapons, such as rocket propelled grenades and the scattering of sub-munitions in different conflict areas have made the clearance of shaped charge ammunition a frequent task. However, unlike other hazards, for shaped charges, EOD personnel lack adequate means for the establishment of the maximum hazardous area and for the design of measures for hazard confinement against the shaped charge effect.

In this article two different models are suggested, which together give guidance for protective measures during clearance of shaped charge ammunition. The development of these models is based on their military utility, by consideration of the limited information availability, the short time frames, the working methods and the technology level that are characteristic for EOD operations. The two suggested models are developed further into a complete set of design rules for protective measures, giving a versatile tool to replace today´s rough estimates and guesswork, in these safety-related decisions.

The clearance of unexploded ordnance (UXO) and other explosive remnants of war (ERW) containing shaped charge warheads poses a particular technical hazard to consider for EOD personnel. The wide use of light anti-tank weapons, such as rocket propelled grenades and the scattering of sub-munitions in different conflict areas have made the clearance of shaped charge ammunition a frequent task. However, unlike other hazards, for shaped charges, EOD personnel lack adequate means for the establishment of the maximum danger area and for the design of measures for hazard confinement against the shaped charge effect. This shortcoming limits the responsible EOD officer to rough estimates and guesswork without scientific support, in these safety-related decisions.

This paper is based on a SNDC military technology thesis, (1). In the thesis two different models, which together give guidance for protective measures during clearance of shaped charge ammunition, are suggested. The development of these models is based on their military utility, by consideration of the limited information availability, the short time frames, the working methods and the technology level that are characteristic for EOD operations.

The first model is intended for use in the design of measures for hazard confinement against jet penetration. The suggested model is derived from a combination of two existing models for the shaped charge effect. A model for shaped charge penetration in single layered media developed by the Swedish Defence Research Agency (FOI) is used as the basis for the model. This is then combined with a modified model that describes how the penetration depth decreases with an increasing stand-off distance. Together they give a simple model for calculating the minimum thickness of barricades and mounds to withstand the penetration of shaped charges at varying distances.

The second model is for estimation of the maximum hazardous area generated by the shaped charge jet. This calculation model is based on the trajectory of the most critical jet segment, i.e. the slug. By defining typical values for those parameters that EOD personnel normally do not have information about, this model can be described with a simple graph. The graph gives the maximum hazardous area based only on the calibre and the elevation of the ordnance. The slug may be stable or unstable in its trajectory - the former giving a significantly larger hazardous area. As the conditions for or the probability of which will apply in a particular case is, currently, not supported by adequate scientific data, figures are given both for a stable and a tumbling slug segment. The use of the figures for an unstable slug will lead to a smaller area at the expense of higher risk.

The two suggested models are developed further into a set of "tools" for the design of protective measures. These tools are adapted to the unique nature of EOD operations, and consist of a complete set of design rules giving a versatile tool to replace today´s rough estimates and guesswork.

A miniature combustor for converting organic samples into CO2 with application in carbon isotopic measurements has been manufactured and evaluated. The combustor was made of High-Temperature Co-fired Ceramic (HTCC) alumina green tapes. The device has a built-in screen printed heater and a temperature sensor made of platinum, co-sintered with the ceramic. A copper oxide oxygen supply was added to the combustor after sintering by in-situ electroplating of copper on the heater pattern followed by thermal oxidation. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Thermal Gravimetric Analysis (TGA) were used to study electroplating, oxidation and the oxide reduction processes. The temperature sensor was calibrated by use of a thermocouple. It demonstrates a temperature coefficient resistance of 4.66×10−3/°C between 32 and 660 °C. The heat characterization was done up to 1000 °C by using IR thermography, and the results were compared with the data from the temperature sensor. Combustion of starch confirmed the feasibility of using copper oxide as the source of oxygen of combustion.

A microscale ceramic high-temperature combustor with a built-in temperature sensor and source of oxygen has been designed, manufactured and characterized. The successful in situ electroplating and oxidation of copper, and the use of copper oxide as the source of oxygen were demonstrated. It was shown that residual stresses from electroplating, copper oxidation and oxide decomposition did not cause much deformation of the substrate but influenced mainly the integrity and adhesion of the metal films. The process had influence on the electrical resistances, however. Calibration of the temperature sensor and correlation with IR thermography up to 1000 °C revealed a nearly linear sensor behavior. Demonstration of combustion in a vacuum chamber proved that no combustion had occurred before release of oxygen from the metal oxide resource.

An aluminium nitride (AlN) passive resonance circuit intended for thermallymatched high temperature wireless sensor nodes (WSN) was manufactured using thick-lmtechnology. Characterization was done for temperatures up to 900C in both a hot-chuck forfrequencies below 5 MHz, and using wireless readings of resonating circuits at 15 MHz, 59 MHz,and 116 MHz. The substrate for the circuits was sintered polycrystalline AlN. Using a simpliedmodel for the resonators where the main contribution of the frequency-shift was considered tocome from a shift of the dielectric constant for these frequencies, the temperature dependency ofthe dielectric constant for AlN was found to decrease with increasing frequency up to 15 MHz.With an observed frequency shift of 0.04% at 15 MHz, and up to 0.56% at 59 MHz over atemperature range of 900C, AlN looks as a promising material for integration of resonancecircuits directly on the substrate.

Hypertext Transfer Protocol Secure (HTTPS) is the de facto standard for secure end-to-end web communication. However, numerous flaws discovered during recent years, such as Apple’s “goto fail” bug, and cryptographic weaknesses as illustrated by the Poodlebleed vulnerability, have brought the efficiency of the mostly self-regulated web security market into question. In this cross-disciplinary paper, the authors survey some 160.000 HTTPS-enabled servers among popular web sites over a time period of three years. The research question is what effect the introduction of best practices and vulnerability publication have on web server security in the form of protocol support. Main findings include that (i) insecure configurations, although well known, can remain widespread for over a decade, (ii) the introduction of best practices affect the decline of insecure configurations only moderately, whereas highly publicized security flaws have a significant impact, and (iii) economic incentives for website owners to provide secure services are weak, motivating such other levers of influence as legislation or blocking of noncompliant sites.

This Letter considers scattered sound from transiently oscillating gas bubbles in liquids. The full transient problem including the finite duration of the excitation is analyzed. As a result, the wave front of the radiated sound pulse involving information about the excitation is also studied. The model presented is used to simulate sound pulses from sea-surface bubbles which have been generated by, for example, spilling breakers, capillary-gravity waves, and rain drops. Although very simple in relation to the actual physical process of excitation, this model enables us to predict some of the essential properties of scattered pulses observed experimentally. It is suggested that the time scale of duration of the initial driving that enters into the present analysis might be of some use in a further physical understanding of bubble generation and excitation.

This investigation concerns free linear gas bubble oscillations in liquids. Of prime interest is the eigenfrequency, and in particular its real part, here named as the transient frequency. The conceptual difference between the more frequently consulted resonance frequency and the transient frequency is first addressed by means of the classical mechanical oscillator. Next, bubble pulsations in liquids are discussed and an existing model is used for the gas-liquid interaction from which an approximate expression for the eigenfrequency is derived. A rationale for the approximate evaluation of the functions modeling the thermal processes is suggested which is independent of the frequency content of any possible pressure excitation, Moreover, compressibility effects are not approximated in the derivation presented here, The quantitative difference between the adiabatic resonance frequency and the derived estimate of the transient frequency is found to be of significance for small bubbles. Finally, the similarity between a standard mechanical oscillator and a bubble in a liquid for the case of liquid-compressibility effects only is discussed.

The relation between the wavefront speed and the group velocity concept is studied in this work. The relationship between the more well-known velocity concept named as the phase velocity and the speed of propagation of a front of an acoustic pulse is discussed. This is of interest since it concerns transient wave propagation and is, in general, not well known. The form and properties of a pulse can be obtained by means of a Fourier integral and estimates based on quantities derived for monochromatic waves, such as the phase velocity, can be severely misleading and confusing. The wavefront velocity is defined as the high-frequency Limit of the phase velocity. This quantity can be far less than the value of the phase velocity for finite frequencies which for example is the case for bubbly fluids. Then the group velocity concept is discussed, which was introduced in order to characterize the propagation of water waves of essentially the same wavelength. However, more confusion occurs in that it is sometimes believed that a wavefront is propagating with the group velocity (a limit process not mentioned) since it can be related to the propagation of energy. This interpretation of energy propagation is based on sinusoidal waves and involves time as well as space averages and is not applicable for pulses. However, by means of the expression for the group velocity given by Stokes it is shown that the speed of a wavefront can be found from the group velocity at a limiting high frequency. This result can be understood geometrically from the definition of the group velocity given by Lamb which is conservation of wavelength. A wavefront is a discontinuity and limiting short wavelengths will be found there.

The Royal Swedish Academy of War Sciences, Division of Military Technology, presents its annual report on the theme "Zero Tolerance for Losses in International Operations". Focus has been on own personnel and losses by combat action.) The study primarily concerns the land arena and the time span 2020-2030. Weapons development continues. The availability of weapons – even advanced ones – increases, also for non-state belligerents. Zero tolerance will require more and more efficient protection solutions to be developed – and to be used to meet increasing threats. Available technology offers many options. Zero tolerance requires high skills of the planner and purchaser, to ensure long-term research and development, timely acquisition and training, and ability to understand potential, limitations, and to adjust tactics accordingly. Holistic systems thinking will be required before, during and after interventions, including staff recruitment, advanced leadership, adequate equipment and high quality training in order to be able to fulfil a difficult mission in the highly complex environment in which the operation will occur.

Weather has a significant influence on navigation processes. Driving dur-ing a heavy rain, for example, is slower and due to poor visibility more dangerous than driving in perfect weather conditions. Thus from time management and safety perspective including weather information is bene-ficial. Weather, especially rain may also be critical for transportation tasks since some commodities like straw or sand should not get wet. In the last years, the quality of weather information and weather forecast has im-proved and could be used to improve route planning. The paper discusses how weather information can be included in route planning algorithms. A first approximating algorithm to incorporate weather forecast data is pre-sented. Some examples showing the impact on route planning conclude the paper.

In military operations, balancing risk is central, and a desire to entirely avoid risk may affect the potential for achieving military goals. Therefore, risk is an important aspect for understanding the operational conditions. This study discusses the assessment of operational risk to support ship design decisions.

Fire is a common consequence of weapon hits and is currently estimated to cause of 80 percent of naval ship loss. The purpose of this study is to describe and investigate the conditions for a risk-based approach to ship fire survivability, that can link probabilistic survivability theory and survivability measure selection. The aim is to suggest key aspects for a risk-based methodology.

To aid in the analysis, this study proposes cause and effect models for the fire risk analysis and describes the fire risk contribution from different types of ignition. The analysis shows that the reliability and validity of identifying potential fires depends on a qualitative and outward-focused analysis of the ships’ intended operation, and the reliability and validity of the analysis on fire consequences depends on the specific data and descriptions used. For example, the magnitude of the fire risk can drastically change due to the operational choices (or unclear operational conditions).

This study concludes that the analysis requires understanding of the operational conditions. Subsequently, civilian risk-based approaches to fire risk are too limited because the approaches do not include aspects of the ship design and intended operation. Further, normal military vulnerability tools lack this ability. However, based on a stringent fire ignition analysis, including a definition of the intended operation, the ship design concept and the threats, civilian methods and tools can be used to assess the consequences.